1. Technical Field
The present invention pertains to infusion devices that enable injection of fluids into an intravenous fluid line during infusion of intravenous solution into a patient. In particular, the present invention is directed toward an infusion warming device for warming infused fluids within a fluid line and including an injection site to facilitate injection of medicaments into the fluid line without compromising infused fluid sterility.
2. Discussion of Related Art
Intravenous (IV) fluids are typically infused into a patient utilizing a liquid-filled bag or container and an IV fluid line. The fluids are generally delivered from the container to the patient via gravitational forces and/or applied pressure. It is important in many situations that the temperature of the intravenous fluid be maintained within a desirable and safe temperature range upon entering the patient body so as to eliminate any potential for thermal shock and injury to the patient.
Accordingly, the related art provides various devices for controlling the temperature of fluid in an IV line for infusion into a patient. One such device employs a heat exchanger to heat and maintain fluid flowing within an IV line at a desired temperature. For example, U.S. Pat. No. 5,063,994 (Verkaart) discloses a heat exchanger including a central tube for carrying an infusate and two outer channels for carrying a heat exchange fluid. A first channel carries the heat exchange fluid from an inlet end to an opposite end, while a second channel returns the fluid to the inlet end. An end cap at the inlet end is connected to a source of heat exchange fluid and communicates with the channels. An end cap at the opposite end receives the heat exchange fluid from the first channel and re-directs the fluid to the second channel. The end caps have connectors for facilitating connection with lines from an infusate source and a patient.
In addition, it may be beneficial or required in certain situations to administer medications or medicaments in combination with IV fluids via the fluid line. Although the Verkaart device warms fluid, there is no provision for enabling administration of medicaments within the fluid. The related art has attempted to overcome this problem by providing infusion warming devices enabling injection of medicaments into an IV line. This is typically accomplished by inserting a syringe needle into a line injection site. For example, the HOTLINE device, available from SIMS Level 1, Inc., includes a heat exchanger employing a layer of circulating warm water surrounding an IV line in order to heat intravenous fluid flowing therein. The device further includes an injection site for receiving a syringe needle. The injection site includes a membrane or seal to accommodate insertion and removal of the syringe needle within that site.
However, this type of device suffers from several disadvantages. In particular, the injection site generally enables syringe needles to compromise intravenous fluid sterility. Specifically, a syringe needle may be inserted within and extend through the injection site, thereby contacting and inadvertently puncturing the IV line. This results in mixing of IV fluid with the surrounding warm water and compromises IV fluid sterility. As a consequence, the patient may suffer adverse affects, including infections and/or illness. In addition, the non-sterile conditions may compromise performance of a medical procedure and/or facilitate extended hospital stays for the patient, thereby substantially increasing medical costs.